Thermo-blower



Dec. 13, 1960 H. COANDA v v 2,964 306 THERMO-BLOWER Filed April 30,19576 Sheets-Sheet 1 Dec. 13, 1960 H. COANDA 1 2,964,306

' THERMO-BLOWER Filed April 30, 1957 r 6 Sheets-Sheet 2 H. COANDATHERMO-BLOWER Dec. 13; 1960 6 Sheets-Sheet 3 Filed April 30, 1957 H.COANDA THERMO-BLOWER Dec. 13, 1960 6 Sheets-Sheet 4 Filed April 30, 1957H. COANDA THERMO-BLOWER Dec. 13, 1960 Filed April so, 1957 6Sheets-Sheet 5 H. COANDA THERMO-BLOWER Dec. 13, 1960 6 Sheets-Sheet 6 1Filed April 30, 1957 FIG."

United THERMO-BLOWER Henri Coanda, Paris, France, assignor to SebacNouvelle ISA? Lausanne, Switzerland, a corporation of Switzer- Theinvention has for its object a thermo-blower de.- vice, that is to say amachine by which a mass of gas may be directed in a predetermineddirection at a given speed, making use of an added quantity of heat.

In his co-pending United States patent application Ser. No. 560,833filed January 23, 1956, now abandoned, the applicant has described athermo-compressor and in his co-pending United States patent applicationSer. No. 598,441 filed July 17, 1956, now Patent No. 2,920,- 448, theapplicant has described a method of effectively setting into motion athigh speed a fluid mass, and a thermo-blower for carrying this methodinto effect; such a thermo-compressor and such a thermo-blower enablemasses of gas to be given a pre-determined direction with a given speed.

The thermo-compressor and the thermo-blower described in the abovementioned patent applications employ the physical effect known as theCoanda effect, which has been described, for example in the U.S. PatentNo. 2,052,869 issued September 1, 1936 to Henri Coanda. It will berecalled that the Coanda effect occurs when a stream of fluid (a gas ora liquid) under pressure leaves a chamber through a slot which has a lipwhich is extended by a wall, the profile of which progressively divergeseither in a continuous manner (curved profile) or in a non-continuousmanner (profile formed by facets), from the direction of emergence ofthe pressure fluid through said slot. The stream of fluid which isdischarged through said slot has a tendency to follow the wall extendingthe lip, and induces some of the surrounding fluid to join the stream.It is thus possible to set in motion and direct a large quantity ofambient fluid with a small mass of fluid under pressure.

The present invention has for its object a new application of the Coandaeffect with a view to the production of a thermo-blower which haspractically no moving parts, that is to say which is a true staticblower, embodiment which has very many advantages. It is well-known thattnost of the known types of compressors comprise membe'rs in rotatingand/or reciprocating movement, which limit their speed of operation andthe temperature which can be permitted in the case in which there is acombustion, since the metallic members in motion are subjected to asubstantial creep beyond a certain temperature. In addition, when thereare parts in movement, it is essential to provide clearances, and theseclearances increase during the course of operation and this has anadverse eifect on the efficiency of the apparatus. Finally, themaintenance of a rotating or reciprocating motion requires anexpenditure of energy which is a pure loss.

The present invention thus enables a static thermo-blower to beproduced, the efiiciency of which is constant, which does not requireanyfenergy to maintain the movement of its parts, which is subjectpractically to no wear, and which reduces to a minimum the costs ofupkeep and of repairs.

A thermo blower in accordance with the invention is atnt 2,964,306Patented Dec. 13, 196() ice discharged under pressure through said slotand the additional ambient fluid which is set in movements, a chamber isprovided into which the said passage discharges; thermal means forincreasing the energy of the mixture in the chamber; and a collectorwhich evacuates from said chamber the mixture, the energy of which hasbeen thus increased and which leads it to a place of utilization.

In a preferred embodiment of the invention the thermoblower is ofsubstantially circular cross-section and it comprises: an annularreceiver containing the compressed gas and arranged around the neck ofan entry portion constituted substantially by a convergent-divergentdischarge-nozzle and discharging in the vicinity of the neck of saidnozzle through a circular slot. The slot has a lip extended by a wallwhose surface progressively diverges in each radial plane from thedirection of emergence of the compressed gas from said receiver throughsaid slot. A circular passage adapted to receive from said inlet themixture of the driving gas and the driven gas. A chamber receives thegaseous mixture from said channel; and a ring of burners incommunication with said chamber increase the energy of the mixture ofgases circulating in said chamber while giving it a gyratory motion.Finally a collector, prefererably of the spiral type, collects the gasesrotating inside the chamber and directs the gases with the desired speedand in the desired direction towards a place of utilization. Thecollector is extended by a divergent passage when so required.

There may of course be provided more than one slot supplied with gasunder pressure in order to effect the setting into motion of the ambientgas towards the circular passage.

7 In certain forms or embodiments, blades or fins may be provideddisposed in said entry portion and/or inside said circular passage so asto give the gases a movement of rotation before their arrival in theannular chamber. Fins or blades may also be provided in the receiver inorder to give a rotational movement also to the gases passing out of thereceiver by the above-mentioned slot.

For certain applications, the gaseous mixture may be caused to pass outof the chamber, which is generally annular, through a slot, usually ofcircular shape, and which also comprises a lip which is extended by awall, a surface of which progressively diverges away, in a radial plane,from the direction of emergence of said mixture through said slot of thechamber, in order to orient the mixture in the desired direction and todraw in a further quantity of ambient gas, which finally enables thedesired mass of gas to be obtained, having the speed required and thechosen direction.

In certain cases, a number of thermo-blowers of one of theabove-mentioned types may be provided on the same apparatus, thesethermo-blowers discharge a gaseous mixture under pressure into acollector. The gaseous mixture passes out of said collector through aseries of annular slots each arranged around a mouth and each comprisinga lip, the extended wall of which progressively diverges from thedirection of emergence .of the gas through said slot (in each radialplane of the said slot), all the mouths being arranged parallel (inorder to discharge through these mouths a series of parallel jets ofgas), or having convergent axes. J

' There will now be described, by way of illustration of thepossibilities of carrying the invention into effect, a few embodimentsthereof, given by way of example and without any implied limitation ofthe scope of the invention, these embodiments being shown in theaccompanying diagrammatic drawings, in which: a a

Fig. 1 is a plan view of a first form of embodiment of a thermo-blowerin accordance with the invention.

. Fig. 2 is a diametral cross-section, taken along the line IIII of Fig.1; a

Fig. 3 is a cross-section similar to that of Fig. 2, showing a devicefor guiding the gases, which can be provided in the thermo-blower inaccordance with the first form of embodiment; 1

Fig. 4 shows diagrammatically aplan view of the guiding device shown inFig. 3;

. a Fig. 5 is a cross-section similar to that shown in Fig. 2, andrelating to a second form of embodiment of a thermo-blower, inaccordance with the invention;

Fig. 6 is a diametral half cross-section of a third form of embodimentof a thermo-blower in accordance with the invention and of one of itsalternative forms;

Fig. 6A is a sectional view taken along lines 6a-6a of Fig. 6;

Fig. 7 is a longitudinal half cross-section of a multiple thermo-blowercomprising a number of units according to the first form of embodiment;

Fig. 8 is a cross-section along theline VIIIVIII of Fig. 7;

Fig. 9 is a cross-section taken along the line IX-IX of Fig. 7;

Fig. 10 shows in cross-section a form of embodiment of a burner whichcan be used in the thermo-blowers shown in the preceding figures, andespecially in that shown in Fig. 6; Fig. 11 gives'a plan view of aparticularv form of embodiment of the coupling between a burner and thechamber into which the gases from the burner are discharged;

Finally, Fig. 12 is a cross-section taken along the line X[IXII of Fig.11. r

In Figs. 1 and 2, there has been shown a first form of embodiment whichcomprises a single annular slot. In this form of embodiment, gas underpressure is led into or produced in the annular receiver 1 from which itis discharged, as shown by the arrows 1', through an annular slot 2, oneof the lips3 of which is extended by a wall 4, the surface of whichmoves or diverges progressively away, in every radial plane, from thedirection of the axis of the outlet of the gases from the receiver 1(direction shown by the chain-dotted line 2').

The wall 4 is. annular and has a constricted annular portion forming aneck 4 with a converging annular portion forming a converging inletpassageway 5 leading into one end of said neck and a diverging annularportion 4" forming a diverging outlet passageway leading out from theopposite end of said neck 4'. The annular slot 2 extends around saidneck and is directed toward said outlet passageway.

Due to the action of the physical effect generally known as the Coandaelfect and described for example in the above mentioned U.S. Patent No.2,052,869, the gas under pressure passing out of the receiver 1, due tothe effect of the lip 3 extended to follow the wall 4, draws-in furtherquantities of gas (for example ambient air) through the inlet 5, thisadditional gas being shown by the arrows 5'.

The gaseous mixture 6' (of the compressed gas 1' discharged from theslot 2 and the additional gas 5) passes into a circular passage or space6 formed, as a continuation of said outlet passageway, between theextended wall 4 and a second wall8. The circular passage 6 opens into anannular chamber 9 which surrounds it and in which the energy of thegaseous mixture is increased by the action of burners 10 which are shownto a larger scale 4 in Fig. 10, these burners having mainly the effect,by the discharge of the burnt gases 10', of imparting to the gaseousmixture 64 a movement of rotation inside the chamber 9, this movementbeing shown by the arrows 9'.

Towards the external wall 12 of the chamber 9, the speed of the gaseousmixture 9' reaches its maximum value, and the gaseous mixture iscollected in a collector 13 of spiral shape, which can eventually beextended by a divergent passageway 14 so as to lead the mixture ofgases, with a speed which is not too high (the reduction in speed takingplace inside the divergent passageway 14), to the place in which it isdesired to utilise it. In the drawing, there has been represented by thearrows 13', 14 and 11' respectively, the gaseous mixture whichcirculates rapidly in the collector 13, slowing-down in the divergentpassageway 14, and finally the usable gaseous mixture passing out of thedivergent passageway.

It can clearly be seen that a compressed gas leaves the receiver 1through the slot 2, carrying with it the additional air 5 and that themixture of compressed gas and additional air moves in a circular passage6, extended by an annular or toric chamber 9, in which the mixture isgiven a supplementary impulse by the burners 10, the gaseous mixturewith the maximum speed being collected in the spiral collector 13.

In order to increase the spiral motion of the gaseous mixture, there isan advantage in placing in the device shown in Figs. 1 and 2, fins orblades arranged in spirals, so that the gases 6, which pass into thechamber 9 have already a movement of rotation. Fins of this kind havebeen shown diagrammatically in Figs. 3 and 4.

Centrifugal fins 15 are generally provided and are fixed in the circularpassage 6 against the wall 8 and, in addition, centripetal fins 16 arepreferably disposed in the inlet 5 in order to give the driven gas 5' amovement of rotation which assists the rotating motion of the mixture 6'of the driven gas 5' and the gas 1 passing out of the slot 2.

In addition, small fins 17 can be arranged in the interior of thereceiver 1 in order to give the gas 1' passing out under pressurethrough the slot 2 a movement of rotation similar to that of the drivengas 5' in order that the flow of the two gases 1 and 5' may not act inopposition at their confluence.

In the case in which all three types of fins 15, 16 and 17 are provided,the gaseous mixture 6 passes into the chamber 9 of Figs. 1 and 2 with ahigh speed of rota; tion, and it only remains for the burners 10 toaccelerate this rotary movement. i

In Fig. 5, there has been shown a second form of embodiment whichcomprises two annular slots 2 and 19 instead of the single annular slot2 of the first form of embodiment. The diametral cross-section shown inFig. 5 is similar to the diametral cross-section of Fig. 2, and thecorresponding parts have been given the same reference numbers in Figs.2 and 5.

In the form of embodiment shown in Fig. 5, gas under pressure passes notonly into receiver 1 but also into the receiver 20, through the conduitsystem 21. The compressed air passes out of the receivers 1 and 29respectively through the slots 2 and 19, each of these slots having oneof the lips 3 or 22 respectively extended by a wall (4 or 23respectively) the profile of said wall diverging continually away (ineach radial plane) from the direction of discharge 2' or 19' of the gasunder pressure, through the slots 2 or 19 respectively.

The mass of air or gas 5 to be drawn-in through the mouth 5 is set intomotion by the above-identified Coanda effect, by the combination of thegases 1 and 20 discharged through the two slots 2 and 19, and it thusbecomes possible to set in motion a mass of air 5' which is much greaterthan in the embodiment of Fig. 1.

The mixture 6' of the compressed gas passing out of the slots 2 and 19and the driven air 5 passes through the circular channel 6 into theannular chamber9, as in the first form of embodiment :of the inventionshown in Figs. 1 and 2.

Burners apply a gyratory force to the mixture 9', and from the peripheryof the chamber 9, this mixture passes into the spiral collector 13 whichleads to the place of use.

Just before the gaseous mixture 6 passes into the chamber 9, it is anadvantage to spray water into it, and to this end there have been shownjets or nozzles 24 supplied from an annular reservoir 25. There may beemployed for example the atomising device described in the US. PatentNo. 2,770,501 issued November 13., 1956 to Henri Coanda. The conversionof the atomised water to steam in the gaseous mixture increases thevolume of this mixture (when considered in the same conditions ofpressure and temperature), and this is an advantage.

In certain applications, the gaseous mixture passing out of thecollector 13, through a divergent 14 where such is provided, does nothave the mass and/or the direction desired. It is then permissible tod.scharge this mixture through one of a number of slots, each slotcomprising a lip which is extended by a wall having a profile whichmoves continually away (in a radial plane) from the direction ofdischarge of the said mixture through the said slot, in order to givethe mixture the desired direction and in order to draw-in furtherquantities of ambient gas through the application of the Coanda effect.Devices of this kind are provided in the embodiments shown in Fig. 6 onthe one hand and Figs. 7, 8 and 9 on the other.

In the embodiment shown in Fig. 6 and Fig. 6a infull lines by adiametral half cross-sectiomseveral modificaare made to the embodimentof Fig. 5. .In Fig. 5 and Figs. 6 and 6a the same reference numbers havebeen given to the corresponding parts.

In the form of embodiment of Figs. 6 and Go, as in that of Fig. 5, thegaseous mixture 6' which circulates in the circular passage 6 resultsfrom the setting in motion of a mass of gas 5' by the gas under pressure1' passing out of the receiver 1 through the slot 2, and by thecompressed gas 28 passing out of the receiver 20 through the slot 19,the slots being disposed as previously described withreference to Figs.1, 2 and 5. This mixture 6' passes into the annular chamber 9 (where itis represented by the arrow 9) in which a portion of the mixture isdivided off at 9", so as to supply the burners 10 which are suppliedwith fuel from a reservoir 26. The burnt gases pass out in the directionof the arrows 10' and give the gaseous mixture 9' a gyratory motion inthe toric chamber 9, thus increasing the energy of the said gaseousmixture.

The arrangement of the burners 10 and the members associated therewithwill be described in more detail below, with reference to Figs. 1O, 11and 1-2.

The mixture of the burnt gases 10 and the gas. 9' passes out of thechamber 9 through a circular slot 27, one of the lips of which 28 isextended by a wall 29, the profile of which is formed by a series offacets, the direction of which moves continually away, in each radialplane, from the direction of discharge 27' of the mixture of It) and 9through the slot 27. By virtue of this arrangement, which enables theCoanda eifect to be applied, the gaseous mass passing out of the slot 27adheres to the wall 29 and carries away a further mass of ambient gas 30through the annular mouth 30. At the downstream extremity 31 of thismonth, there is thus obtained a considerable mass of a gaseous mixturehaving the desired direction as shown by the arrows 31.

In a further alternative embodiment the continuous circular slot 27 maybe replaced by a series of. slots of arcuate form, separated by solidportions and arranged on the same circle or on separate circles.

In a further alternative form of this embodiment shown in Fig. 6, aseries of discharge nozzles 32 may be pro- 'vided (in Fig. 6, there isshown one such discharge nozzle 32, indicated in broken lines), theconvergent intakes 33 of which communicate with the surrounding air, andwhich 'pass into the vicinity of the burners 10 and discharge at 34 in'the'vicinity of the downstream extremity 31 of the mouth 30.

In this alternative form, the gaseous mass 31' carries along anadditional mass .29 of ambient gas which passes in the direction of thearrows 33 into the convergent intake 33, and which is heated in thedischarge nozzle 32 in the vicinity of the burners 10 at the level ofthe chamber 9. There is thus obtained a greater total mass of gas by theuse of the discharge nozzles 32.

In Figs. 7., 8 and 9, there has been shown an embodiment in which anumber of th'ermo-blowers 35 of one 'of the foregoing types areprovided, for example "of the type shown in Figs. 1 and 2, each blowerdischarging, through a collector 13 and a divergent passageway 14, into'a toric channel 36, a mixture of :gases under pres sure (as is shownespecially in Fig. 9). In order to prevent vortex and gyratory motionsin the channel 36, the thermo-blowers are preferably arranged in pairs,the collectors and the direction of rotation of the gases beingclockwise in one of the thermo-blowers and anti-clockwise in the otherthermo-blower of each pair.

The mixture of gases under pressure passes out of the channel '36through a series of annular "slots 37 arranged aroundconvergent-divergent mouths of discharge nozzles 38, and each having alip 39, the extended wall 40 of which becomes continually further away,in a radial place of the slot. From the direction of discharge ofthegaseous mixture through said slot, so that, by the operation of the'Coanda eifect, the mixture 36' of gas under pressure carries along theambient gas 38' and so that the mixture 41' of 36 passes out from thedivergen't extremity 41 of each discharge nozzle 38 downwards (in Fig.8) with the desired speed. The discharge nozzles 38 may be arrangedparallel to each other, or alternatively they may be arranged onconcurrent axes.

In Figs. 10 to 12, there has been shown on a largerscal'e a burner 10and its possible means of coupling to the chamber 9. The form ofembodiment shown of the burner -10 and its associated parts isespecially suitable for the thermo-blower shown in Fig. 6.

The burner 10 comprises a cylindrical chamber 42 enclosed by a doublewall 43'a43b. The fuel 44' is led from a reservoir 26, through thepiping system 44 of which one portion 44a is formed by a coil arrangedbetween the walls 43a and 43b, to an injector 45 controlled by a needle46; The fluid of combustion is formed by one portion 9" of the mass ofgaseous mixture 9' which circulates in the chamber 9, this portion beingdelivered through a divergent nozzle 46 (in order to reduce its speed)into the annular chamber 47 which is enclosed between the two walls 43aand 43b. This gaseous mixture leaves the chamber 47 through orifices 48formed in the wall 43b, "and allows the combustion to take place, afterignition, of the jet of fuel 49 discharged by the injector 45.

The combustion which takes place in the chamber '42 enables the fuel inthe coil 44a and the air of combustion in the chamber 47 to bepreheated, which increases the thermal efficiency of the burner. Theburnt gases 10' 'pass out at the extremity 50 of the burner 10;

As shown in Figs. 11 and 12, the coupling between each burner 10 and thechamber 9 can be of flattened shape and the gases 10 may pass out ofeach burner 10 through a linear slot 51, of which one of the lips 52diverges from the discharge axis 54 of the gases 10 through the slot'51, as shown at51, in order to apply a more powerful driving action onthe gaseous mixture 9' in the chamber 9. In order to prevent anyin-draught from acting on the mass of gas in movement, walls 53 arearranged on the sides of theextended lip 52.

.,As previously, indicated, the burners 10 are preferably orientated inthe direction of movement of the gas in the chamber 9,'with a slighttendency to discharge towards '7 the external wall 12 in order tofacilitate the'passa'ge' of the gaseous mixture 910' into the collector13.

It will of course be understood that a number of changes, improvementsor additions may be made to the forms of embodiment described and shown,or certain devices may also be replaced by equivalent devices, withoutthereby modifying the general scope of the invention;

For example in the form of embodiment of Figs. 7 to 9, the gaseousmixture could pass out of the channel 36 through a series of dischargenozzles having either a fixed direction or being orientable at will inorder to obtain the desired effect.

What I claim is:

1.' A thermoblower comprising in combination, a first annular wallhaving a constricted annular portion forming a neck, a convergingannular portion forming a converging inlet passageway leading into oneof said neck and a diverging annular portion flaring radially outwardlyand forming a diverging outlet passageway leading out from the oppositeend of said neck, a second wall spaced from said outwardly flaringportion of said first wall to define between said walls an outwardlyflaring annular space forming a continuation of said outlet passagewayand an annular chamber which surrounds said annular passageway and intowhich said annular passageway opens, the neck portion of said first wallhaving formed therein an annular slot extending around said neck anddirected toward said outlet passageway, said slot having spaced lips, anannular receiver surrounding said neck and communicating with said slot,said receiver being adapted to receive gaseous fluid under pressurewhich is discharged through said slot into said neck, the lip of saidslot on the side toward the outlet end of said neck and an adjacentannular portion of said first wall defining a surface whichprogressively diverges from the direction of emergence of said pressurefluid through said slot so that a stream of fluid discharged throughsaid slot tends to follow said surface and to induce adjacent fluid insaid neck to join in the stream, thereby drawing additional gaseousfluid through said inlet passageway and neck, said stream of pressurefluid and additional fluid flowing outwardly through said dischargepassageway and annular passageway and discharging into said annularchamber, heating means disposed to heat said fluid in said annularchamber, and thereby increase its kinetic energy, means defining adischarge outlet opening outwardly from said annular chamber and meansfor collecting fluid discharged from said chamber and directing ittoward a place of utilization.

2. A thermoblower according to claim 1, in which said heating meanscomprise a plurality of burners, means to provide fuel to the burners,and further including for each burner a speed-reducing divergent devicecommunicating with said chamber for providing some of the gaseous fluidin said annular chamber to a respective burner to support combustiontherein.

3. A thermoblower according to claim 1, in which said heating meanscomprise a plurality of angularly spaced burners each having acylindrical housing with an open end through which hot gases aredischarged mounted on one of said walls defining said annular chamberwith said open end opening into said chamber, each said burner having alongitudinal axis inclined to said wall on which the burner is mountedin a direction toward said discharge outlet opening so that hot gasesissuing from said burners mix with gaseous fluid in said annular chamberand implement flow of the resulting mixture toward said discharge outletopening.

4. A thermoblower according to claim 3, in which said housings each havea flattened divergent end portion having said open end in communicationwith the annular chamber, said end portion having said open end formedas a linear slot opening into the annular chamber, said linear slothaving in an axial section through said housing end portion an extendedlip surface which progressively diverges from the direction of emergenceof gases into said annular chamber from the respective burners so thatthe gases tend to follow said surface into said chamber.

5. A thermoblower comprising in combination, a first annular wall havinga constricted annular portion forming a neck, a converging annularportion forming a converging inlet passageway leading into one end ofsaid neck and a diverging annular portion flaring radially outwardly andforming a diverging outlet passageway leading out from the opposite endof said neck, a second wall to define between said walls and outwardlyflaring annular space forming a continuation of said outlet passagewayand an annular chamber which surrounds said annular passageway and intowhich said annular passageway opens, the neck portion of said first wallhaving formed therein an annular slot extending around said neck anddirected toward said outlet passageway, said slot having spaced lips, anannular receiver surrounding said neck and communicating with said slot,said receiver being adapted to receive gaseous fluid under pressurewhich is discharged through said slot into said neck, the lip of saidslot on the side toward the outlet end of said neck and an adjacentannular portion of said first wall defining a surface whichprogressively diverges from the direction of emergence of said pressurefluid through said slot so that a stream of fluid discharged throughsaid slot tends to follow said surface and to induce adjacent fluid insaid neck to join in the stream, thereby drawing additional fluidthrough said inlet passageway and neck, said stream of pressure fluidand additional fluid flowing outwardly through said discharge passagewayand annular passageway and discharging into said annular chamber,heating means disposed to heat said fluid in said annular chamber andthereby increase its kinetic energy, means defining a discharge outletopening outwardly from said annular chamber and spiral-shaped means forcollecting fluid discharged from said chamber and directing it toward aplace of utilization, and said collecting means having walls divergingtoward said place of utilization.

6. A thermoblower comprising in combination, a first annular wall havinga constricted annular portion forming a first neck, a converging annularportion forming a converging inlet passageway leading into one end ofsaid first neck and a diverging annular portion flaring radiallyoutwardly and forming a diverging outlet passageway leading out from theopposite end of said first neck, a second wall spaced from saidoutwardly flaring portion of said first wall to define between saidwalls an outwardly flaring annular space forming a continuation of saidoutlet passageway and an annular chamber which surrounds said annularpassageway and into which said annular passageway opens, said secondwall having a constricted annular portion forming a second necksubstantially coaxial with the first-mentioned neck and a portiondefining a first receiver communicating with said constricted annularportion disposed leading into said second neck and adapted to receivegaseous fluid under pressure, the neck portion of said first wall havingformed therein an annular slot extending around said first neck anddirected toward said outlet passageway, said slot having spaced lips, anannular second receiver surrounding said first neck and communicatingwith said slot, said second receiver being adapted to receive gaseousfluid under pressure which is discharged through said slot into saidfirst neck, the lip of said slot on the side toward the outlet end ofsaid first neck and an adjacent annular portion of said first walldefining a surface which progressively diverges from the direction ofemergence of said pressure fluid through said slot so that a stream offluid discharged through said slot tends to follow said surface and toinduce adjacent fluid in said first neck to join in the stream, therebydrawing additional fluid through said inlet passageway and neck, meanscoaxial with said second neck forming an annular second slot extendingaround said second neck, the second wall having an annular portiondisposed forming an outlet of said second neck defining a surface whichprogressively diverges from the direction of emergence of said pressurefluid through said second annular slot so that a stream of fluiddischarged through said second slot tends to follow said surface and toinduce adjacent fluid in said passageway to join in the stream, saidstreams of pressure fluid and additional fluid flowing outwardly throughsaid discharge passageway and annular passageway and discharging intosaid annular chamber, heating means disposed to heat said fluid in saidannular chamber and thereby increase its kinetic energy, means defininga discharge outlet opening outwardly from said annular chamber and meansfor collecting fluid discharged from said chamber and directing ittoward a place of utilization.

References Cited in the file of this patent UNITED STATES PATENTS2,097,255 Saha Oct. 26, 1937 1 2,639,084 MacKenzie May 19, 1953 02,676,007 Davis Apr. 20, 1954

